An important step in the manufacture of a precision optical instrument is the accurate installation of the finished lens in its mount. The mounting process, however often results in slight misalignments which require further adjustment. To compensate for the inaccuracies in the mounting process, the lens mount or holder is finished after the lens is mounted. This is generally performed on a centering lathe in preparation for the finish turning of the circumference of the mount. It is necessary to align the optical axis of the lens as closely as possible with the mechanical axis of the mount to insure that the lens/mount assembly can be accurately aligned in proper relation to the optical axis of the instrument during its assembly.
In the systems of the prior art, as shown in FIG. 1, the lens assembly is adjustable in the lathe on a fixture which allows limited movement to affect alignment. A light beam is directed to the lens by a collimator which also collects the reflected light and directs it to a display. The display gives a visible indication of the deviation of the optical axis of the lens from the axis of the collimator which is coincident with the mechanical axis of the lathe. The position of the lens assembly is adjusted by manually tapping the fixture with a mallet or other suitable device. The display is observed during the tapping to determine when the adjustment is complete. This is a time consuming process which is dependent on the skill of the operator and accordingly lacks consistency.
It is the purpose of this invention to automate this alignment process and to provide a simple effective method and apparatus to accomplish the centering step accurately and quickly while controlling the adjustment to reduce human error.